1. Field of the Invention
The present invention relates to a writable-once optical disc and a management information recording method and apparatus, and more particularly, to a method and apparatus for efficiently recording disc usage management information on a writable-once optical disc.
2. Discussion of the Background Art
Optical disc, which is a kind of optical recording media and can record a large amount of data, is widely being used. Today, a kind of innovative high-density digital versatile disc (HD-DVD) such as a blue ray disc (Blu-ray Disc), which can record and store video data of high quality and audio data of high fidelity for a long time, is under development.
The Blu-ray disc is a next generation optical recording solution that can store a larger amount of data than a conventional DVD. The Blu-ray disc employs a blue-violet laser with the wavelength of 405 nm which is shorter than the wavelength of 650 nm of a red laser used to access a conventional DVD. The Blu-ray disc has generally a thickness of 1.2 mm and a diameter of 12 cm. It includes a light transmission layer whose thickness is 0.1 mm so that the Blu-ray disc can store a larger amount of data than the current DVDs.
Various standards related to the Blu-ray discs are in development. Among the different types of Blu-ray discs, a Blu-ray Disc Rewritable (BD-RE) and a Blu-ray Disc Write-Once (BD-WO) are being developed.
FIG. 1 schematically illustrates a structure of a recording area of a general BD-RE. Referring to FIG. 1, the BD-RE includes a recording layer divided into a lead-in area, a data area and a lead-out area. The data area includes a user data area for recording user data thereon, and an inner spare area ISA0 and an outer spare area OSA0 each allocated in the inner tracks and the outer tracks of the disc. These spare areas are used as replacement areas for replacing data in a defective area of the user data area according to linear replacement.
In the BD-RE, if a defective area is found in the user data area during recording, data in the defective area is transferred to and recorded on a spare area using linear replacement. Further, as defect management information for managing the defective area, position information and the like relating to the defective area and the corresponding spare area are recorded on defect management areas (DMA 1˜DMA 4) in the lead-in area and the lead-out area. Also, since data can be recorded on and erased from any area of the BD-RE repeatedly (since the BD-RE is rewritable), the entire BD-RE can be randomly used irrespective of a specific recording mode.
In contrast, in a writable-once Blu-ray disc (BD-WO), data can be recorded only one time on a specific area of the disc. As a result, the BD-WO has certain limitations pertaining to recording modes and in randomly using the entire area of the disc due to the defect management difficulty.
Further, in a BD-WO, management of the defective areas is one of the important matters that needs to be addressed, especially for data recording operations. But since the BD-WO is still in the early development stage, there are no schemes, no disc structures, no apparatuses, and no methods on how to manage the defective areas of the BD-WO, which will be needed for the BD-WO to be commercially viable and operationally feasible. Accordingly, for the BD-WO, a unified specification is required that would satisfy the aforementioned advanced requirements. But any proposed specification relating to the current BD-RE cannot be used because it does not address the needs of the BD-WO.